The first known examples of dreadlocks go back to Africa from the beginning of time since Locked hair is a natural result when letting it grow and leaving it uncombed, as the comb and scissors were later inventions and physical appearance was not important in the early development of human beings, this must have been the common appearance. Later when societies developed and had the tools and need to cut hair, it became more common to have short or styled hair. But Locks must have been a natural throughout all times and societies in Africa. in ancient Egypt examples of Egyptians having locked hair have appeared on artifacts as well as mummified remains from archaeological sites.
In various religions it was and still is common that priests or monks have their hair Locked, example’s of this are the monks of the Ethiopian Orthodox Tewahedo Church and Muslim Sufis.  
Biblically, Samson was described having 7 Locks, and also noteworthy are descriptions in the Bible of James the Just, brother of Yahshua and first Bishop of Jerusalem, who wore Locks to his ankles.

RASTAFARI

DreadLocks are one of Rastafari main identifying Signs, it is a sign of devotion to the most High YAH and is often seen as a kind of seal in the relationship between the two (like the Sabbath). Other then this ordained Sign between Ysrayl and YAH it symbolizes Rebel-lion against babylon setting InI apart from mainstream society. It also symbolizes the manes of Lion, identifying I&I self with Emperor Haile Selassie I who is the Lion of Yahuda. Rastafari often see themselves as kind and humble Lions when not disturbed, but causing terrible judgment when provoked, in likeness of His Majesty. Rastafari also grow Locks for spiritual reasons, saying that the length of our hair can have influence on someone’s spiritual state of being, seeing locks as spiritual antenna’s that reach into the heavens making it easier to connect with YAH. It is taught that patience is the key to growing Locks, and can be seen as a spiritual journey with the mind, soul and body.
Some view the length of someone’s Locks to be an indication of wisdom and maturity, as that it reveals that an individual has set him/herself far from babylon teachings for a good while and should have gained plenty of Rastafari teachings during this time. For Rastafari Growing Locks is often seen a very serious principle with a lot of meaning to it. 

NAZARITE VOW

Some say that Rastafari got the idea of growing Locks from a news publishing in Jamaica about MauMau warriors that fought in Kenya against colonialism in 1940.
Although this might have had some influence the main reason why Rastafari have Locks is because of Biblical guidance within scripture like Leviticus 21:5 ("They shall not make baldness upon their head, neither shall they shave off the corner of their beard, nor make any cuttings in the flesh.") and the Nazarite vow in Numbers 6:5 ("All the days of the vow of his separation there shall no razor come upon his head: until the days be fulfilled, in which he separateth himself unto the Lord, he shall be holy, and shall let the Locks of the hair of his head grow."). When accepting the Nazarite Vow, one becomes a Nazarene that is separated from the world but lives closer to YAH.
Hair Naturally Locks when it is not trimmed and combed, so this must have been very common in Biblical times as the Nazarite vow has been given a lot of value and therefore must have been followed by many people wanting to devote their lives to YAH. Therefor the Incients must have looked like how Rastafari do today and a black, Locked and bearded Christ is a more realistic image then of the more known (white) jesus.

PERSECUSION

In Jamaica, the ruling society and eurocentric culture labeled the hairstyle as “dreadful” in appearance, and were thought to be disgusting and frightening, hence the term ‘dread’or dreaded which gave birth to the modern name 'dreadlocks'. The police used it as an immediate way to locate those who were not interested in partaking of “normal” society. The early Rastafari were the first protesters in Jamaica by claiming their identity through I&I hair . Rastafari received heavy persecution just for being who we are. Without having committed a crime, Rastafari were brutalized, mistreated and detained by the police, often cutting off I&I Locks in public.

FASHION DREADS

Today dreadlocks are well excepted and has become a fashion statement for many people, we overstand that this is only natural and don't have big a problem with it. But we are bothered when people look at anyone with dreads or has a Rasta appearance, as Rastafari, because most are not and don't live by the examples that we as Rastafari stand for. These are ones that might like the vibes and culture and may be Reggae fans, going to Reggae festivals and concerts, they might be wearing a Bob Marley t shirt or wear something Red, Gold and Green. But for many the livety ends there, and these individuals will be eating meat, drinking heavily, misbehaving, disrespecting woman, causing trouble and more embarrassment...can't ask them much about the livety because they haven't studied I&I and the knowledge is not there. This is something to be aware of, we expect plenty people won't be so shortsighted to think this. But still we also know there are enough that are. So we feel a necessity to make people aware of this, also the ones causing this confusion by motivating them to show more interest in the Rastafari livety and not only the reggae and party scene.
Locks worn for stylish reasons without principal meaning  are sometimes referred to as "bathroom locks," or sometimes such dreadlocked individuals are called "wolves", as in a wolf in sheep's clothing. 
Dreadlocks are a sign of something good like Rastafari, something to be proud of and to look up to, a sign of detachment from the babylon system, and wisdom... But could also be worn by the most evil man or woman, just how a bold man can be the most righteous.
So even if Locks are an important aspect of the Rastafari livety, we don't haffi Dread to be Rasta, we haffi be Good to be Rasta.
There are some differences in opinion about this, and some will say that one needs to have Locks to be Rastafari because it is such a big part of the livety and has such an important role with a lot of meaning to it, that it cant be excluded.
Some Rastafari might not grow Locks for practical reasons, usually because we won’t get a job as easy or not at all in certain segments of society, especially if we have freeform Locks (that are usually thicker and wilder, more dreadful). The neatly twisted Locks have become socially accepted by now and wont always be such a hinder in getting work. But if we have to choose between survival in the babylonian system (in the sense of needing money to pay for bills and food) and having Locks some will choose survival instead. It is not always an easy choice to make, but some people have big responsibilities for instance in taking care of I&I family.  

STYLES

There are different styles how one's can have I&I Locks,

Freeform is the most ancient and usually worn by the elders, in which the hair is grown and washed without interference from one trying to style it, leaving it to form freely and gives it a unique character.

Twisted Locks are more popular with the younger generation or ones living in suburban areas.
This method is usually done without the use of utensils, no cutting, combing or brushing, but simply by washing the hair with pure water, handpalming and twisting the Locks to speed up the process and to give the desired look that suits the individual.

Breaded Locks, Some might first bread the hair and then leave it to lock, or first twist them and then bread them, this is often preferred by females. It also has some Biblical value wherein breaded locks are mentioned.

People with straight hair may need to use some kind of tool to help Lock the hair, by using the back combing method or Locking the hair with a Croix hook. Certain wax (like beeswax) can  assist the Locking process, but is not really recommended as the wax is difficult to wash out and has the tendency to hold on to dirt. 

MAINTANANCE

For Rastafari, one of our values, or principles, is that we keep things as pure and as clean as possible, especially when it comes to our Locks. We Rastafari have high regard for cleanliness (for cleanliness is godliness).
To give our Locks a good cleansing, we can use apple cider vinegar. The vinegar gets into the Locks the same way as water but the apple cider is very cleansing. We can also use the gel from the aloe plant or if we buy something in the store, something as natural as possible and a moisturizer is also good.

If we want neat Locks they need much maintenance by giving them lots of love, and attention. keeping them lint free, the root Locked, twisting them, washing, drying, keeping them moisturized. Always dry the locks thoroughly after washing them, as moist locks that are covered or bound together can get muff and a bit smelly (not dirty).

Patients is the key to having nice Locks, they won't look like we want right away, we have to give them plenty of time to grow and develop and keep maintaining them. 

Dreadlocks have become increasingly popular and there are many reasons in various cultures for wearing them. They can be an expression of deep religious or spiritual faith, a manifestation of ethnic pride. They can make a political statement, or simply be a fashion preference.

For InI Rastafari it is our Birthright.